The use of bath salts - synthetic cathinones with effects similar to methamphetamine and cocaine - has been associated with violent behavior, emergency hospitalizations and some fatalities among youth and adults in various parts of the country. In response, several state and local governing bodies and the federal government recently legislated bans on the active chemical ingredients in bath salts. These measures have created a new illicit drug market, which may significantly affect user experiences. Most of what is known about bath salts to date comes from emergency room reports and mass media coverage of extreme user experiences. However, it is also important to understand the experiences of users who may not end up in emergency rooms but who may be incurring other, as yet unknown, health risks related to the drugs. Scientific research to date is focused on toxicology, which is vitally important, given that bath salts makers frequently adjust the ingredient chemicals in order to evade law enforcement. Little is known, however, about the developing illicit market, or about subcultural and other social contexts that affect user experiences. The mixed-methods, 5-year investigation proposed here will start to fill that knowledge gap, by meeting the following aims: A. (Drug Market Integration) To scientifically document the integration of bath salts into the illicit drug markets, identify and document commonplace varieties of bath salts that are being sold, how they are sold, quantities being sold, variation in prices, access to products, street/brand names and name changes and how dealers manage users; B. (Role of Violence) To delineate the role of violence and document how and under what circumstances such violence co-occurs with bath salts use/sales, and how the illicit market manages such behaviors; a comparison with crack and methamphetamine will be examined to document how the market adjusts to integrate such behaviors; C. (Use Practices) To document use practices (set and setting) and conduct norms among bath salts users and to identify health problems occurring over time associated with use. Recruitment and data collection will be evenly divided among 4 cities: New Orleans, Houston, Galveston (TX) and New York. The research team has previously conducted market studies in all of these cities and has well established contacts among illicit drug users and sellers. Methods will include ethnography (n=80), focus groups (n=200) and survey (n=1,000). This study will complement ongoing toxicology research into bath salts, consistent with NIDA's mission to apply science to questions of drug abuse and addiction, and to do so in a cross-disciplinary way. Understanding subcultural and social contexts of bath salts use, including user perceptions and expectations, will serve the long-term goal of developing and implementing highly targeted prevention messages and treatment strategies.